Synthesis and Characteristics of CaAl2O4:Eu3+ Phosphor Prepared by Zol-Gel Method

2015 ◽  
Vol 670 ◽  
pp. 95-100 ◽  
Author(s):  
Lyudmila N. Mishenina ◽  
Liliya A. Selyunina ◽  
Tatiana M. Botvina
Keyword(s):  
Alkaline Earth ◽  
Annealing Temperature ◽  
Sol Gel ◽  
Earth Metal ◽  
Rare Earth Ions ◽  
Spectrometric Analysis ◽  
X Ray Diffraction ◽  
Gel Method ◽  
X Ray ◽  
Uv Excitation

Alkaline earth metal aluminates activated by rare-earth ions (REn+) possess intensive luminescence upon UV excitation. The paper studies phase formation of calcium aluminate prepared by the sol-gel method. The stages of the end products’ formation using methods of the thermal and the infrared spectrometric analysis and X-ray diffraction are proposed. Dependence of phase composition, the surface morphology and luminescence properties on the annealing temperature of the precursor is investigated.

Conductivities of Titanium Dioxide Obtained via the Sol-Gel Method

2012 ◽  
Vol 545 ◽  
pp. 143-147
Author(s):  
Annie Maria Mahat ◽  
Kelimah Elong ◽  
Nor Diyana Abdul Aziz ◽  
Mohd Sufri Mastuli ◽  
Norlida Kamarulzaman
Keyword(s):  
Titanium Dioxide ◽  
Single Phase ◽  
Annealing Temperature ◽  
Sol Gel ◽  
X Ray Diffraction ◽  
Rutile Structure ◽  
Gel Method ◽  
X Ray ◽  
Sol Gel Method ◽  
Impedance Technique

Titanium dioxide powders were synthesized via a sol-gel method using titanium nitride as the precursor. The structure and morphology of the synthesized powders were investigated and characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM). XRD results indicate that pure single phase titanium dioxide of rutile structure had been obtained. It was also revealed that annealing temperature plays an important role in the formation of single phase titanium dioxide powders. Increasing heat treatments also modified the shape and surface morphology from chunks and rock-like morphology to a mixture of flaky aggregates. Conductivity studies using a.c. impedance technique was used. The conductivity of the sample annealed at 400 °C is 89 % higher than that annealed at 800 °C and attributed to the phase and morphology of the samples.

scholarly journals The Role Sol-gel Method and Doping Ba in the Drastic Reduction of the Annealing Time and the Improvement of the Coupling Between Grains of Bi1.6Pb0.4 Sr2-xBaxCa2Cu3Oy Superconductor 

2020 ◽  
Author(s):  
seyed ebrahim Mousavi Ghahfarokhi ◽  
Saeedeh Zamani
Keyword(s):  
Magnetic Susceptibility ◽  
Annealing Temperature ◽  
Sol Gel ◽  
Ac Magnetic Susceptibility ◽  
X Ray Diffraction ◽  
Drastic Reduction ◽  
Gel Method ◽  
X Ray ◽  
Sol Gel Method ◽  
The Stability

Abstract In this study, the Bi1.6Pb0.4Sr2-xBaxCa2Cu3Oy superconductors with x = 0.0, 0.05, 0.1, 0.15, 0.2, 0.25, and 0.3 were synthesized at annealing times of 32, 48, 64 h using a sol-gel method. Then, the effect of Ba doped, the annealing times, ac magnetic fields and frequencies in the improvement of the coupling between grains of the Bi1.6Pb0.4Sr2-xBaxCa2Cu3Oy (BPSBCC) superconductors were studied. In order to determine annealing temperature, TGA analysis of x = 0.0 was performed. The structural and ac magnetic susceptibility prepared samples were characterized using an X-ray diffraction, an ac susceptometer and scanning electron microscopy (SEM). The results of ac magnetic susceptibility and structural of the samples indicated that the improvement of the coupling between grains and the stability of the Bi1.6Pb0.4Sr2-xBaxCa2Cu3Oy superconductors with value of x = 0.2 at 845 °C for 48 h have been increased.

Photoluminescence of Eu3+-Doped TiO2 Thin Films Prepared by Sol-Gel Method

2010 ◽  
Vol 150-151 ◽  
pp. 707-710
Author(s):  
Dan Hong Wang ◽  
Xiao Ru Zhao ◽  
Hui Nan Sun ◽  
Li Bing Duan ◽  
Chang Le Chen
Keyword(s):  
Thin Films ◽  
Doping Concentration ◽  
Annealing Temperature ◽  
Anatase Phase ◽  
Sol Gel ◽  
X Ray Diffraction ◽  
Tio2 Thin Films ◽  
Gel Method ◽  
X Ray ◽  
Sol Gel Method

The sol-gel method was employed to prepare the Eu3+-doped TiO2 thin films. The influence of doping concentration and annealing temperature on the structures and photoluminescence (PL) properties was investigated. The result of X-ray diffraction revealed that all the films are of anatase phase. It is shown that the PL intensities of the films increased with Eu3+ concentration and reached the maximum at 1.4 mol%, then decreased with the concentration. Observed anatase phase appeared at temperature above 400 °C, and the luminescence intensity increased with the increase of annealing temperature.

Annealing Effects on the Physical and Magnetic Properties of Tb1.5Y1.5Fe5O12 Films Nanoparticles Prepared by Sol-Gel Method

2013 ◽  
Vol 756 ◽  
pp. 91-98 ◽  
Author(s):  
Ftema W. Aldbea ◽  
Noor Bahyah Ibrahim ◽  
Mustafa Hj. Abdullah
Keyword(s):  
Particle Size ◽  
Magnetic Properties ◽  
Annealing Temperature ◽  
Quartz Substrate ◽  
Sol Gel ◽  
Lattice Parameter ◽  
Gel Method ◽  
X Ray ◽  
Sol Gel Method ◽  
Iron Garnet

Terbium –substituted yttrium iron garnet (Tb1.5Y1.5Fe5O12) films nanoparticles were successfully prepared by a sol-gel method. The films were deposited on the quartz substrate using spin coating technique. To study effect of annealing temperature, the annealing process was executed at 700, 800 and 900 °C in air for 2 hours. The X-ray diffraction (XRD) proved that the pure phase of garnet structure was detected for the film annealed at 900 °C. The lattice parameter increased with the increment of annealing temperature and the highest value of 12.35 Å was obtained at 900 °C. Field Emission Scanning Electron Microscope (FE-SEM) results showed that the particle size increased from 43nm to 56nm as annealing temperature increased from 700 to 900°C. The film’s thickness also affected by increasing of annealing temperature and become thin at 900 °C due to densification process occurred at high annealing temperature. The elemental compositions of the Tb1.5Y1.5Fe5O12 film were detected using an Energy Dispersive X-raySpectroscopy (EDX). Magnetic properties at room temperature were measured using a Vibrating Sample Magnetometer (VSM).The saturation magnetization Ms increased with the annealingtemperature and showed a high value of 104emu/cm3, but the coercivity Hc of the film was decreased due to the increment of the particle size. Normal 0 21 false false false MS X-NONE X-NONE MicrosoftInternetExplorer4 Terbium –substituted yttrium iron garnet (Tb1.5Y1.5Fe5O12) films nanoparticles were successfully prepared by a sol-gel method. The films were deposited on the quartz substrate using spin coating technique. To study effect of annealing temperature, the annealing process was executed at 700, 800 and 900°C in air for 2 hours. The X-ray diffraction (XRD) proved that the pure phase of garnet structure was detected for the film annealed at 900 °C. The lattice parameter increased with the increment of annealing temperature and the highest value of 12.35 Å was obtained at 900 °C. Field Emission Scanning Electron Microscope (FE-SEM) results showed that the particle size increased from 43nm to 56nm as annealing temperature increased from 700 to 900 °C. The film’s thickness also affected by increasing of annealing temperature and become thin at 900 °C due to densification process occurred at high annealing temperature. The elemental compositions of the Tb1.5Y1.5Fe5O12 film were detected using an Energy Dispersive X-ray Spectroscopy (EDX). Magnetic properties at room temperature were measured using a Vibrating Sample Magnetometer (VSM).The saturation magnetization Ms increased with the annealing temperature and showed a high value of 104emu/cm3, but the coercivity Hc of the film was decreased due to the increment of the particle size. st1\:*{behavior:url(#ieooui) } /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-qformat:yes; mso-style-parent:""; mso-padding-alt:0cm 5.4pt 0cm 5.4pt; mso-para-margin:0cm; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:11.0pt; font-family:"Calibri","sans-serif"; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso-fareast-font-family:"Times New Roman"; mso-fareast-theme-font:minor-fareast; mso-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin; mso-bidi-font-family:"Times New Roman"; mso-bidi-theme-font:minor-bidi;}

Impedance Spectroscopy Study of LiTaO3 Powder Synthesized via Sol-Gel Method

2012 ◽  
Vol 545 ◽  
pp. 275-278 ◽  
Author(s):  
Lili Widarti Zainuddin ◽  
Norlida Kamarulzaman
Keyword(s):  
Room Temperature ◽  
Single Phase ◽  
Sol Gel ◽  
Rhombohedral Structure ◽  
Spectroscopy Study ◽  
X Ray Diffraction ◽  
Gel Method ◽  
X Ray ◽  
Sol Gel Method ◽  
Impedance Spectroscopy Study

A ceramics sample of LiTaO3 was prepared using a sol-gel method. The sample is annealed at 750 °C for 48 hours. X-ray diffraction analysis indicate the formation of single phase, rhombohedral structure. An ac impedance study was used to analyse the conductivity of LiTaO3 at room temperature and at various temperatures.

Magnetic Properties of Bulk Zn0.95-XMnXFe0.05O2 Prepared by Sol-Gel Method and Subsequent Hot Pressing

2011 ◽  
Vol 268-270 ◽  
pp. 356-359 ◽  
Author(s):  
Wen Song Lin ◽  
C. H. Wen ◽  
Liang He
Keyword(s):  
Magnetic Properties ◽  
Photoelectron Spectroscopy ◽  
Raw Materials ◽  
Sol Gel ◽  
Secondary Phase ◽  
X Ray Diffraction ◽  
Gel Method ◽  
X Ray ◽  
Sol Gel Method ◽  
Doped Zno

Mn, Fe doped ZnO powders (Zn0.95-xMnxFe0.05O2, x≤0.05) were synthesized by an ameliorated sol-gel method, using Zn(CH3COO)2, Mn(CH3COO)2and FeCl2as the raw materials, with the addition of vitamin C as a kind of chemical reducer. The resulting powder was subsequently compacted under pressure of 10 MPa at the temperature of 873K in vacuum. The crystal structure and magnetic properties of Zn0.95-xMnxFe0.05O2powder and bulk samples have been investigated by X-ray diffraction (XRD) and vibrating sample magnetometer (VSM). X-ray photoelectron spectroscopy (XPS) was used to study chemical valence of manganese, iron and zinc in the samples. The x-ray diffraction (XRD) results showed that Zn0.95-xMnxFe0.05O (x≤0.05) samples were single phase with the ZnO-like wurtzite structure. No secondary phase was found in the XRD spectrum. X-ray photoelectron spectroscopy (XPS) showed that Fe and Mn existed in Zn0.95-xMnxFe0.05O2samples in Fe2+and Mn2+states. The results of VSM experiment proved the room temperature ferromagnetic properties (RTFP) of Mn, Fe co-doped ZnO samples.

scholarly journals Effect of Preheating Temperature on Synthesis of Pure BiFeO3 via Sol–Gel Method

Nanopages ◽  
2019 ◽  
pp. 1-11
Author(s):  
G. M. Taha ◽  
M. N. Rashed ◽  
M. S. El-Sadek ◽  
M. A. Moghazy
Keyword(s):  
Electron Microscope ◽  
Transmission Electron Microscope ◽  
Sol Gel ◽  
X Ray Diffraction ◽  
Pure Bifeo3 ◽  
Gel Method ◽  
X Ray ◽  
Sol Gel Method ◽  
Transmission Electron ◽  
Preheating Temperature

Abstract BiFeO3 (BFO) nanopowder was synthesized in a pure form via a sol- gel method based on glycol gel reaction. Effect of drying and preheating temperature on preventing other phases was studied. Many parameters were studied as calcination temperature and time & stirring temperature as well. The prepared powder was characterized by X-Ray Diffraction of powder (XRD) and Transmission Electron Microscope (TEM). High pure BiFeO3 was obtained by preheated process at 400 °C for 0.5 h and calcination at 600 °C for 0.5 h without any impurities compared to dry at110 °C.

Effect of Synthesis Conditions on the Structure and Electrochemical Properties of LiNi1/2Mn1/2O2 by Sol Gel Method

2011 ◽  
Vol 399-401 ◽  
pp. 1447-1450
Author(s):  
Zhi Yong Yu ◽  
Han Xing Liu
Keyword(s):  
Electrochemical Properties ◽  
Sol Gel ◽  
Electrochemical Analysis ◽  
X Ray Diffraction ◽  
Capacity Fading ◽  
Gel Method ◽  
X Ray ◽  
Sol Gel Method ◽  
Synthesis Conditions ◽  
A Current

The layered LiNi1/2Mn1/2O2 cathode materials were synthesized by a sol gel method. The effects of calcination temperature and time on the structural and electrochemical properties of the LiNi1/2Mn1/2O2 were investigated. The prepared samples were characterized by X-ray diffraction (XRD) and electrochemical analysis. The results revealed that the layered LiNi1/2Mn1/2O2 material could be optimal synthesized at temperature of 900°C for 10h. The sample prepared under the above conditions has the highest initial discharge capacity of 151 mAh/g and showed no dramatic capacity fading during 20 cycles between 2.5-4.5V at a current rate of 20mA/g.

scholarly journals The Influence of Annealing Temperature on the Structure and Magnetic Properties of Nanocrystalline BiFeO3 Prepared by Sol–Gel Method

2021 ◽  
Author(s):  
T. Pikula ◽  
T. Szumiata ◽  
K. Siedliska ◽  
V. I. Mitsiuk ◽  
R. Panek ◽  
...  
Keyword(s):  
Grain Size ◽  
Magnetic Properties ◽  
Annealing Temperature ◽  
Sol Gel ◽  
Weak Ferromagnetism ◽  
X Ray Diffraction ◽  
Gel Method ◽  
Sol Gel Method ◽  
Average Grain Size ◽  
Spin Cycloid

AbstractIn this work, BiFeO3 powders were synthesized by a sol–gel method. The influence of annealing temperature on the structure and magnetic properties of the samples has been discussed. X-ray diffraction studies showed that the purest phase was formed in the temperature range of 400 °C to 550 °C and the samples annealed at a temperature below 550 °C were of nanocrystalline character. Mössbauer spectroscopy and magnetization measurements were used as complementary methods to investigate the magnetic state of the samples. In particular, the appearance of weak ferromagnetic properties, significant growth of magnetization, and spin-glass-like behavior were observed along with the drop of average grain size. Mössbauer spectra were fitted by the model assuming cycloidal modulation of spins arrangement and properties of the spin cycloid were determined and analyzed. Most importantly, it was proved that the spin cycloid does not disappear even in the case of the samples with a particle size well below the cycloid modulation period λ = 62 nm. Furthermore, the cycloid becomes more anharmonic as the grain size decreases. The possible origination of weak ferromagnetism of the nanocrystalline samples has also been discussed.

scholarly journals The Variation Effect of Mg-doped NPs Prepared by Sol-Gel Method on its Structural Properties and Biological Activities

2021 ◽  
Vol 2114 (1) ◽  
pp. 012004
Author(s):  
Duha S. Ahmed ◽  
Noor Q. Ali ◽  
Ali A. Taha
Keyword(s):  
Biological Activities ◽  
Sol Gel ◽  
Spherical Particles ◽  
X Ray Diffraction ◽  
Gel Method ◽  
X Ray ◽  
Sol Gel Method ◽  
Nio Nps ◽  
Dopant Element ◽  
Mg Doped

Abstract In this paper, we reported the synthesis of NiO NPs and Mg doped-NiO NPs using the facile sol-gel method. Besides, the influence of the variation of Mg dopant on the structural, morphological and optical properties of the prepared Mg-NiO NPs was studied. The synthesized Mg-NiO NPs nanoparticles were characterized by X-Ray Diffraction Analysis (XRD), Energy Dispersive X-ray Spectroscopy (EDS), Fourier-Transform Infrared Spectroscopy (FTIR), Field-Emission Scanning Electron Microscopy (FE-SEM), and UV-Vis spectrophotometer. The X-ray diffraction confirmed the formation of the cubic structure of Mg doped-NiO NPs after doping with the magnesium. The increase in the crystal size was observed with the increase in the concentration of the Mg dopant element. The FESEM images reveal the formation of nickel oxide through the appearance of spherical clusters, while the hybrids appear as wrinkled surface covered with spherical particles of magnesium. The UV-Vis spectrum showed a shift towards shorter wavelengths with an increase in the concentration of the Mg dopant element due to the quantum confinement effect. The hemolysis activity study showed that NiO NPs had a low hemolysis percentage of 1.47% and increased with increasing concentration. While, increasing of the RBC hemolysis (5.9%) after NiO doped with Mg. The antibacterial activity was studied against S. aureus and P. aeruginosa bacteria, and indicated the highest growth inhibition zones of Mg-doped NiO NPs as compared with NiO NPs against of Staphylococcus aureus and Pseudomonas aeruginosa, respectively.

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